Discipline: Veterinary Medicine
The gallbladder in the Philippine water buffalo was a pear-shaped organ on the visceral surface of the liver between the right and quadrate lobes. It measured 15.8 ± 0.28 cm long and 7.6 ± 0.26 cm wide in the male buffaloes and 15.1 ± 0.30 cm long and 7.4 ± 0.21 cm wide in the female buffaloes. Without bile, the gallbladder weighed 85.5 ± 0.95 g in males and 84.4 ± 0.9 g in females and with bile it weighed 233.7 ± 6.22 g in males and 221.3 ± 5.21 g in females. The gallbladder was vascularized by the cystic artery, a branch of the gastroduodenal artery. The wall of the gallbladder was composed of tunica mucosa, lamina propria-submucosa, tunica muscularis and tunica serosa (for the free surface) and tunica adventitia (for the attached surface). The tunica mucosa was lined by tall columnar epithelium consisting chiefly of tall columnar cells, clear cells, and a few intraepithelial lymphocytes. The lamina muscularis mucosa was absent. The lamina propria-submucosa contained numerous diffuse or nodular lymphatic tissues, Rokitansky-Aschoff sinuses and mixed tubuloalveolar glands. The tunica muscularis was composed of an outer layer of compact longitudinally-arranged muscle bundles and an inner layer that consisted of an outer circularly arranged muscle fibers and an inner longitudinally arranged muscle fibers. The tunica serosa and adventitia presented no striking features. The epithelium and glands in the lamina propria-submucosa reacted positively to periodic acid Schiff (PAS), alcian blue CAB) pH 1.0 and 2.5 stains. The histology of the gallbladder of the Philippine water buffalo is generally similar to that of cattle described in various veterinary textbooks.